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csquared

Rough shells

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Hello all!

I just received my UM2 and am having some issues achieving high quality prints.

All of my prints are printing with rough non uniform surfaces, and horizontal bands.

 

fruit juicers

 

The fruit juicer on the left is from my Rep2 and the one on the right is from my UM2

 

 

My settings are:

 

0.1mm Layer height

210 Hotend

60 Bed

50mm/s Speed

Acceleration turned down to 3000 to prevent ringing.

 

Any help would be much appreciated!

 

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Is the left one also ABS? I wouldn't be surprised if ABS is easier on overhangs.

1) For good quality overhangs you need TONS of fan. Was the fan set to 100%? Was it blowing (not sucking)? Were both fans working?

2) You can improve quality a bit by lowering temperature and speed. The acceleration on the UM2 is probably much higher than your reprap. So printing at 100mm/sec on reprap is probably like 30mm/sec on UM2. At least for small parts. Anyway try 30mm/sec - that's a nice slow speed for when you want good visual quality. 210C is a good temp but you could always try lower. Consider printing some test overhang parts.

3) This is not the best filament for overhangs (ultimaker light blue). Consider a different color or brand but I don't recommend switching to ABS before using the printer for at least 10 different parts. Switching to ABS (and especially back again) can cause clogged nozzle or partial clogs that hinder extrusion.

4) Was the juicer on left at .1mm or .2mm layer height?

 

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Oh - and regarding that horizontal line - that's not good. That looks like the Z stage got stuck for one layer. Is there plenty of grease on your z screw? Your printer should have come with a little green pouch of grease - meant only for the

Z screw.

 

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Sorry I forgot to mention that they are both printed in PLA and at .1mm layer height.

As for the overhangs I was actually more referring to the overall quality of the outer shell aside from the overhangs, its not nearly as smooth as the juicer printed on the Replicator 2. The layers are a lot more .....apparent I guess, not sure what the right word is to describe it. My fans are working, all three are blowing.

Here is a close up of what I am talking about.

photo

I am currently printing a vase at .1mm layer height 200 degrees and 25mm/sec and am getting the same results.

Everything I've printed so far just hasn't come out as "smooth" as I am used to at a .1mm resolution.

I really appreciate your help so far, thank you very much!

 

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Horizontal banding caused by a partially stuck z stage (as gr5 described) is much better visible in prints made from light colored PLA (especially pastel colors) than in those made from dark material. It's a question of the master batch used which alters the flow behavior.

I also have this issue with my UM2 (http://umforum.ultimaker.com/index.php?/topic/6907-horizontal-banding-on-um2/). However, as I just reoiled the z screw this weekend and it didn't go away I now focus on the z nut. IMHO this is a very cheap part with not very high quality. It has quite some play (up to a millimeter in my case). I submitted a ticket to Ultimaker this weekend asking how much play is normal in that part. I'm seriously considering replacing the standard z nut with a anti-backlash z nut.

 

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Okay then try that darker blue filament! Or is it 1.75mm filament?

 

Unfortunately it is 1.75mm.

I seem to have gotten rid of most of the banding but it still just doesn't look up to par. I printed the cups both at .1mm layer height and 25mm/sec at 210 and also raised the temp to 220 to see if that had any affect.

They both look like someone used an old paintbrush with old paint and you can see the brush strokes left behind. Its interesting because it looks as tho a lot of the rough bits don't make it all the way around the layer. It looks like some of the layers are bulging out.

Is this just the way the UM2 prints and I'm just being picky?

photo

 

Horizontal banding caused by a partially stuck z stage (as gr5 described) is much better visible in prints made from light colored PLA (especially pastel colors) than in those made from dark material. It's a question of the master batch used which alters the flow behavior.

I also have this issue with my UM2 (see here). However, as I just reoiled the z screw this weekend and it didn't go away I now focus on the z nut. IMHO this is a very cheap part with not very high quality. It has quite some play (up to a millimeter in my case). I submitted a ticket to Ultimaker this weekend asking how much play is normal in that part. I'm seriously considering replacing the standard z nut with a anti-backlash z nut.

 

I greased the Z stage and checked it for any play and everything looks to be OK. Im curious as to how your situation works out and if your problem and mine are related.

Thanks again for everyone's help thus far!

 

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I don't get that banding - certainly not at 35mm/sec. I suspect I don't get it at any speed but I just looked around at a bunch of parts and ones I printed at 50mm/sec or faster are all small (only 10mm tall) or don't have smooth faces so it's hard to be sure.

I don't get banding on UM Original and I don't get it on UM2. Well - I get a tiny amount but the vertical banding is more prominent.

I would expect this kind of banding if the temperature is varying by 10C or more. Also if the Z stage isn't moving properly. Did you try sliding the Z stage up and down by hand? Grip it towards the back. See if there is extra resistance somewhere.

 

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I don't get that banding - certainly not at 35mm/sec. I suspect I don't get it at any speed but I just looked around at a bunch of parts and ones I printed at 50mm/sec or faster are all small (only 10mm tall) or don't have smooth faces so it's hard to be sure.

I don't get banding on UM Original and I don't get it on UM2. Well - I get a tiny amount but the vertical banding is more prominent.

I would expect this kind of banding if the temperature is varying by 10C or more. Also if the Z stage isn't moving properly. Did you try sliding the Z stage up and down by hand? Grip it towards the back. See if there is extra resistance somewhere.

 

Z stage moves very smoothly by hand and doesn't seem to get stuck or resist at any point.

Something I did just notice is that my Y motors shaft/pulley wobbles, I cant tell if it is the shaft on the motor or the pulley is malformed. When you move the print head by hand you can feel the wobble as well.

 

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Sorry for the radio silence, life has been quite busy. I'm still having my Z banding issue and am having a hell of a time figuring it out.

Here's one of my latest prints any help more help at this point would be much appreciated.

This was printed at .1 resolution 35mm/sec and a I varied the temperature during the print between 210c and 235c to see if it would have any impact on my issue.

IMG 0747

 

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I Am having this exact issue. My brand new UM2 has been doing it since new. I am now negotiating with my local dealer to replace the unit. They have now even changed my entire z axis to no result! Who did you buy the printer from?

 

Sorry for the radio silence, life has been quite busy. I'm still having my Z banding issue and am having a hell of a time figuring it out.

Here's one of my latest prints any help more help at this point would be much appreciated.

This was printed at .1 resolution 35mm/sec and a I varied the temperature during the print between 210c and 235c to see if it would have any impact on my issue.

IMG 0747

 

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